var useBSNns;

if (useBSNns)
{
	if (typeof(bsn) == "undefined")
		bsn = {}
	var _bsn = bsn;
}
else
{
	var _bsn = this;
}


_bsn.Crossfader = function (divs, fadetime, delay )
{	
	this.nAct = -1;
	this.aDivs = divs;
	
	for (var i=0;i<divs.length;i++)
	{
		document.getElementById(divs[i]).style.opacity = 0;
		document.getElementById(divs[i]).style.position = "absolute";
		document.getElementById(divs[i]).style.filter = "alpha(opacity=0)";
		document.getElementById(divs[i]).style.visibility = "hidden";
	}
	
	this.nDur = fadetime;
	this.nDelay = delay;
	this._newfade();
}


_bsn.Crossfader.prototype._newfade = function()
{
	
	if (this.nID1)
		clearInterval(this.nID1);
	
	this.nOldAct = this.nAct;
	this.nAct++;
	if (!this.aDivs[this.nAct])	this.nAct = 0;
	
	if (this.nAct == this.nOldAct)
		return false;
	
	document.getElementById( this.aDivs[this.nAct] ).style.visibility = "visible";
	
	this.nInt = 50;
	this.nTime = 0;
	
	var p=this;
	this.nID2 = setInterval(function() { p._fade() }, this.nInt);
}


_bsn.Crossfader.prototype._fade = function()
{
	this.nTime += this.nInt;
	
	var ieop = Math.round( this._easeInOut(this.nTime, 0, 1, this.nDur) * 100 );
	var op = ieop / 100;
	document.getElementById( this.aDivs[this.nAct] ).style.opacity = op;
	document.getElementById( this.aDivs[this.nAct] ).style.filter = "alpha(opacity="+ieop+")";
	
	if (this.nOldAct > -1)
	{
		document.getElementById( this.aDivs[this.nOldAct] ).style.opacity = 1 - op;
		document.getElementById( this.aDivs[this.nOldAct] ).style.filter = "alpha(opacity="+(100 - ieop)+")";
	}
	
	if (this.nTime == this.nDur)
	{
		clearInterval( this.nID2 );
		
		if (this.nOldAct > -1)
			document.getElementById( this.aDivs[this.nOldAct] ).style.visibility = "hidden";	
		
		var p=this;
		this.nID1 = setInterval(function() { p._newfade() }, this.nDelay);
	}
	if (this.stopping)
	{
		if (this.nTime == this.nDur)
		{
			clearInterval( this.nID1 );
			clearInterval( this.nID2 );
		}
	}
}

_bsn.Crossfader.prototype._easeInOut = function(t,b,c,d)
{
	return c/2 * (1 - Math.cos(Math.PI*t/d)) + b;
}

function stopFader(target, navdiv)
{
	target.stopping=true;
	if (target.nTime<target.nDur)
	{
		//alert(target.nTime);
		document.getElementById( target.aDivs[target.nAct] ).style.opacity = 1;
		document.getElementById( target.aDivs[target.nAct] ).style.filter = "alpha(opacity="+(100)+")";
		if (target.aDivs[target.nOldAct])
		{
			document.getElementById( target.aDivs[target.nOldAct] ).style.opacity = 0;
			document.getElementById( target.aDivs[target.nOldAct] ).style.filter = "alpha(opacity="+(0)+")";
			document.getElementById( target.aDivs[target.nOldAct] ).style.visibility = "hidden";
		}
	}
	target.nTime=0;
	clearInterval( target.nID1 );
	clearInterval( target.nID2 );
	
	document.getElementById(navdiv).style.visibility='visible';
}
function startFader(target, navdiv)
{
	target.stopping=false;
	target.nTime=0;
	clearInterval( target.nID1 );
	clearInterval( target.nID2 );
	target.nID1 = setInterval(function() { target._newfade() }, target.nDelay);
	document.getElementById(navdiv).style.visibility='hidden';
}
function nextDiv(target, navdiv)
{
	target.nOldAct = target.nAct;
	target.nAct++;
	if (!target.aDivs[target.nAct])	target.nAct = 0;
	document.getElementById( target.aDivs[target.nOldAct] ).style.opacity = 0;
	document.getElementById( target.aDivs[target.nOldAct] ).style.filter = "alpha(opacity="+(0)+")";
	document.getElementById( target.aDivs[target.nOldAct] ).style.visibility = "hidden";
	document.getElementById( target.aDivs[target.nAct] ).style.opacity = 1;
	document.getElementById( target.aDivs[target.nAct] ).style.filter = "alpha(opacity="+(100)+")";
	document.getElementById( target.aDivs[target.nAct] ).style.visibility = "visible";
	document.getElementById(navdiv).style.visibility='hidden';
}
function prevDiv(target, navdiv)
{
	target.nOldAct = target.nAct;
	target.nAct--;
	if (target.nAct<0) target.nAct=target.aDivs.length-1;
	document.getElementById( target.aDivs[target.nOldAct] ).style.opacity = 0;
	document.getElementById( target.aDivs[target.nOldAct] ).style.filter = "alpha(opacity="+(0)+")";
	document.getElementById( target.aDivs[target.nOldAct] ).style.visibility = "hidden";
	document.getElementById( target.aDivs[target.nAct] ).style.opacity = 1;
	document.getElementById( target.aDivs[target.nAct] ).style.filter = "alpha(opacity="+(100)+")";
	document.getElementById( target.aDivs[target.nAct] ).style.visibility = "visible";
	document.getElementById(navdiv).style.visibility='hidden';
}